Continuous Movement of the Toes

In this case, we present a 26-year-old African American male with an 18-month history of constant involuntary alternating dorsiflexion-plantar flexion movements of his left toes, especially the big toe. With manual interference and conscious attention, he could eliminate the movement. He had dull pain in the left lower extremity, but no urge to move his left foot or toes.

The patient had a temporary response to a dopamine agent that lasted one month. Neurological examination revealed a decreased light touch sensation on his feet, otherwise unremarkable. Results from MRI of the brain and spine, EEG, nerve conduction studies, and electromyography were normal. Other test results were unremarkable, as was family history.

The most likely diagnosis is:

1. Epilepsy partialis continua

2. Restless leg syndrome

3. Akathisia

4. Painful legs and moving toes syndrome

5. Spinal segmental myoclonus

6. Chorea

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The correct answer is: 3. Madras motor neuron disease.

Painful legs and moving toes syndrome (PLMT) is rare and characterized by involuntary and irregular movements of toes and variable pain of the foot and leg. Movements affect toes more than the foot and often appear as a continual wriggling and writhing motion. The pain tends to be continuous and throbbing in nature, varying in intensity.1,2 The etiology of PLMT remains unknown, but it is associated with peripheral neuropathies, radiculopathies, and trauma.2,3 It is diagnosed by history and physical examination alone. Complementary studies are rarely necessary.

Of note, PLMT exhibits features similar to other movement disorders: Epilepsia partialis continua (EPC) presents as repetitive and rhythmic movements of the foot or toe(s), lesion(s) on brain MRI, and abnormal EEG findings (epileptic discharges and/or slow activity). This patient’s toes wriggle and writhe, rather than move rhythmically; this coupled with normal complementary studies does not suggest EPC. Restless leg syndrome (RLS) presents as an urge to move the legs. The sensation is relieved somewhat with activity, feels worse with inactivity, and worsens at night. The lack of urge to move limbs (rather, toes moved continuously), the lack of worsening with inactivity, and absence of circadian awake/sleep pattern weights against RLS. In addition, RLS rarely affects only one leg, and even more rarely just the toes.

Akathisia is state of inner sense of body restlessness caused by neuroleptics’ exposure or withdrawal, lithium, and serotonin reuptake inhibitors. Patients present with whole body movement, rocking, and general fidgetiness. This patient was not taking any akathisia-induced medications, and his abnormal movement was restricted to the toes on his left foot, which is rarely seen in those with akathisia.

Spinal segmental myoclonus presents as involuntary fast rhythmic or semi-rhythmic jerky movements of a muscle group of one or few myotome(s) innervated by a segment of the spinal cord. It is usually associated with structural abnormalities of the spinal cord (i.e., myelitis, neoplasm, and trauma). Spinal myoclonus does not present as toe wriggling and writhing of the toes.

Chorea presents as continuous flowing-character movement—non-stereotypical in nature—that affects the whole body or half of the body, rather than the toes.

Khizar Malik, MD is a neurologist at the Orlando Veterans Affairs Medical Center in Orlando, Florida.

Cara Sherrill is a medical school student at the University of Central Florida Medical School.

Fabian H. Rossi, MD is Director Clinical Neurophysiology Laboratory at the Orlando VA Medical Center. He is also an Associate Professor of Neurology at UCF Medical School.